Prior art remote controlled, video monitored weapon systems have generally involved a combination of a whole television camera and a conventional weapon. Such combinations are inherently so bulky and space-consuming, both in the axial and vertical depth directions that they have not been usable for anti-hijacking purposes in commercial airplanes. There is simply not enough space available in the ceiling area of the conventional airplane to accommodate such TV camera/weapon combination therein. It was inconceivable that such a bulky combination could be adapted to linear travel, pan and tilt movements so as to cover the entire passenger compartment area of an aircraft, or that it could be obscured from view of the passengers behind a one-way vision screen. Similarly, the amount of space occupied by such prior art television camera and conventional weapon combinations generally precluded the adaptation thereof for protective systems to be used in banks, prisons, stores, office buildings, or the like.
All prior art remote control, video monitored weapon systems of which the applicant is aware could be seen by a potential hijacker or criminal or the like, and hence could be defended against by retaliatory action, or could be avoided, so as to minimize the effectiveness thereof. A further problem in connection with these prior art weapon systems utilizing a TV camera and conventional type weapon, relates generally to the optics thereof. Such prior art systems embodied vertically or laterally spaced optical and weapon axes, thereby having a parallax inaccuracy inherent in the aiming thereof. This becomes a critical problem in a remote controlled weapon system for aircraft protection, because of the necessity for pinpoint accuracy to avoid damaging critical aircraft parts, and to be assured of a completely incapacitating offensive action against a hijacker or the like without danger to other occupants. This parallax problem becomes more acute as the weapon is moved closer to the subject in an attempt at increased accuracy.
The optics problem associated with a conventional television camera-weapon combination also involves an orientation problem between the subject as viewed by the television camera and the subject as displayed on a remote video monitor. Tilting movements of the television camera, and particularly tilting movements beyond the vertical axis, and also panning movement beyond 90.degree., with the conventional television camera optics employed in such prior art camera-weapon combinations, tended to provide a badly disoriented image at the remote monitoring station, making it difficult to track a subject in movement, and often dangerous to employ the weapon.
Prior art automatically operable weapons in general are not of unobstructed tubular configuration, and hence are incapable of having coaxially arranged optics directly mounted therein. Thus optical aiming systems for automatic weapons are conventionally laterally or vertically offset from the firing axis of the weapon, requiring that the reticle in any optical scope aiming system associated therewith also be spaced from the firing axis. Such spacing not only involves a parallax problem between reticle and weapon axis, but also involves a sometimes even more serious axial alignment problem. This can raise doubts as to the accuracy of alignment and aiming, where such doubts cannot be tolerated in the close confines and with the critical surrounding areas in an aircraft protective system. The requirement of axially offset optics with conventional automatic weapons also detracts from the compactness thereof, making them further unsuitable for use in a protective system for aircraft or the like.
Referring particularly to the commercial aircraft protection problem, the protective measures currently in use are (1) attempting to identify and observe persons who are considered by mannerism or appearance to be of a high risk "type" likely to be involved in hijacking; (2) inspecting the persons and/or baggage of airplane passengers; (3) the use of sky marshals riding the aircraft; and (4) the use of snipers to shoot hijackers if they can be lured out of the airplanes.
All of these currently used measures have serious drawbacks. In order to be effective, baggage and personal inspections are much too time-consuming to be used on any substantial scale and yet be compatible with heavy airline schedules as presently followed. Attempting to identify and watch high risk type persons is a very chancy thing, as often a hijacker will look like a very ordinary person. FBI agents have sniped or shot at hijackers with high powered rifles from strategic airport locations whenever possible, but this requires that the hijacker be lured out of the airplane, which only occasionally occurs.
The sky marshal approach has been used extensively, and it has the advantage of providing offensive action against a hijacker when the hijacker has been positively identified during flight. However, sky marshals have a tendency to place everyone in the airplane under great risk, and their effectiveness has proven to be quite limited in scope for a number of reasons. Thus, the sky marshal cannot take offensive action without danger of retaliatory action from the hijacker either against the sky marshal or perhaps indiscriminately against one or more passengers, or against a hostage. Another problem is that a weapon in the hand of a sky marshal tends to be unstable, being adversely affected by turbulence, the urgency of the situation, the danger to other persons or aircraft systems, and the like. The sky marshal cannot always choose the time or place to act, and he can be seen and acted against by the hijacker. Also, once the sky marshal precipitates action against a hijacker, he has no choice but to proceed, despite dangers that may arise to passengers. Because the sky marshal can be seen by the hijacker, it is difficult for him to cope with or to avoid the hostage problem. Finally, the deterrent effect of a sky marshal is minimal, because a potential hijacker is aware of the sky marshal's limitations, and can retaliate and defend against him.